package com.wy.shiro.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

/**
 * 登陆验证码工具类
 */
public class LoginAuthCodeUtil {

	/**
	 * 随机数字字母
	 */
	private static char mapTable[] = { 'a', 'b', 'c', 'd', 'e', 'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u',
	        'v', 'w', 'x', 'y', 'z', '0', '2', '3', '4', '5', '6', '7', '8', '9' };

	/**
	 * 验证码图片
	 */
	public static String getCertPic(int width, int height, ByteArrayOutputStream byteArrayOutputStream) {
		if (width <= 0) {
			width = 60;
		}
		if (height <= 0) {
			height = 22;
		}

		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		// 获取图形上下文
		Graphics g = image.getGraphics();
		// 设定背景颜色
		g.setColor(new Color(0xDCDCDC));
		g.fillRect(0, 0, width, height);
		// 画边框
		// g.setColor(Color.black);
		// g.setColor(new Color(2, 67, 121));
		// g.drawRect(0, 0, width-1, height-1);
		// 随机产生的验证码
		String strEnsure = "";
		// 4代表4位验证码,如果要生成等多位的验证码 ,则加大数值

		for (int i = 0; i < 4; i++) {
			strEnsure += mapTable[(int) (mapTable.length * Math.random())];
		}
		// 将验证码显示在图像中,如果要生成更多位的验证码,增加drawString语句
		g.setColor(new Color(0x003399));
		g.setFont(new Font("Atlantic Inline", Font.PLAIN, 18));
		String str = strEnsure.substring(0, 1);
		g.drawString(str, 8, 17);
		str = strEnsure.substring(1, 2);
		g.drawString(str, 20, 15);
		str = strEnsure.substring(2, 3);
		g.drawString(str, 35, 18);
		str = strEnsure.substring(3, 4);
		g.drawString(str, 45, 15);
		// 随机产生10个干扰点

		Random random = new Random();
		for (int i = 0; i < 10; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			g.drawOval(x, y, 1, 1);
		}
		// 释放图形上下文
		g.dispose();
		try {
			// 输出图像到页面
			ImageIO.write(image, "JPEG", byteArrayOutputStream);
			byteArrayOutputStream.flush();
			byteArrayOutputStream.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return strEnsure;
	}
}